Some USB devices just take more power for no good reason. I have a 2GB flash drive and a 4GB flash drive. Guess which one wants too much power to work right with my N800? the 2GB drive. I also have an extensions cable that appears to have a high enough resistance that it causes devices that normally work with my N800 to fail. The N8x0s are pretty picky about what they work with, but when things work they seem pretty reliable.

-John